Long time back when IRC was in use, we had server operators removing bots from IRC channels. It was easy to discover a bot as when you ping them on direct message they were not able to have good conversation with you. They were multiple simple AI systems that tried to emulate human but it was easy to discover that it is a bot. One botnet came up with solution that was brilliant. Put bot on few channels and it someone start talking to it, have the bot randomly outreach person who is active from different channel. Then rely conversation between them as man-in-the-middle, just changing the nicknames. You could have full conversation with actual person and it was hard to spot that it's a bot:-)